Pressure heating device



Jan. 25 1944. GRAPP 2,340,120-

PRESSURE HEATING DEVICE Filed'Nov. 8, 1940 2 Sheets-Sheet 1 Jan. 25, 1944. L. GRAPP 2,340,120

PRESSURE HEATING DEVICE Filed Nov. 8, 1940 2 Sheets-Sheet 2 I77 #2775127 l/L'RBER'TL. G f

vqffarn 5/ Patented Jan. 25, 1944 UNITED STATES BATE-NT? OFFICE PRESSURE HEATING DEVICE Herbert L. Grapp, Minneapolis Minn; Application November 8, 1940, Serial No. 364,838

4 Claims.

This invention relates to an air heating device and particularly to an air heating device where the fuel such as a gaseous fuel is burned under pressure and the heated air is maintained under pressure. .By thus having the air to be heated and the fuel as well as the air of combustion under'pressure, much higher efiiciency is secured in the. heating process. By having the air at ten pounds pressure it is possible to get substantially ten times the B; t. u.s in one cubic foot of air that can be had at atmospheric pressure. The efiect of burning gas under pressure is to increase the flame temperature and shorten the distance from particle to particle, or the distance of flame travel. Consequently the velocity of combustion is increased and more fuel can be burned in a given space. While air has been previously heated in chambers by means of fuel burners it is believed new to confine the air under pressure and heat the same by burning the fuel under pressure.

It is an object of this invention to provide an air heating device comprising a casing with a chamber therein, means for supplying air to said chamber under pressure, air by burning the fuel under pressure, together with means for regulating the pressure on the burner to prevent back pressure thereon and to secure the desired character of flame.

It is more specifically an object of the invention to provide a casing preferably of cylindrical form having a chamber therein, a member projecting into said chamber usually lined with refractory material, aburner in said passage for burning gas under pressure and supplied with air under pressure, means for supplying air under pressure to said chamber adjacent said member and a baffle member surrounding said member and extending therefrom in said chamber movable toward and from said member for regulating the air pressure at said burner.

It is also an object of the invention to provide an air heating device comprising a casing having a chamber therein in which air under pressure is heated, said chamber being provided with explosion means comprising a passage leading from said chamber having a screen thereacrossand a diaphragm of frangible material overlying said screen.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which: 7

means for heating said Fig. 1 is a plan view of the device;

Fig. 2 is a view in sideelevation thereof, some parts being omitted, and some being shown in section on line 2-2 of Fig. 1;

Fig. 3 is a horizontal section taken substantially on line 3-3 of Fig. 2;

Fig. 4 is a view in rear elevation, some parts being omitted;

Fig. 5 is a vertical section taken substantially on line 5-5 of Fig. 3 as indicated by the arrows;

the explosion heads, some parts being broken away; and

Fig. 7 is a vertical section taken on line 'I-'I of Fi 6. 1

Referring to the drawings an air heating device is shown comprising a casing Ii]. While this casing might take various forms, in the embodiment of the invention illustrated it is shown as of cylindrical form having a contracted outlet end, the same'being shown with a thick insulated wall Illa. At the inlet end of the cham--. her a member I! is provided shown as disposed in or projecting into chamber Ifib of casing It member II being lined with firebrick I2 or other suitable refractory material. A rear cover Iilc is provided for casing I O which will be held in place by nuts I3 placed on projecting studs I l, only a few of nuts I3 being shown. Another plate It is secured to plate I00, plate I5 also being held in place by a plurality of nuts IB- placed on projecting studs I 1. Plate I5 has secured thereto a burner casing I8, a portion of which projects into the passage in member II. A pipe I9 is connected to a-coupling 25, in turn connected to member I 8, the same being provided with a control valve 2I and said pipe I9 will-be connected to a suitable supply of gas under pressure. A conduit 23 is provided which will be supplied with air under pressure, said conduit being shown as having therein a T coupling 2a which coupling has secured to one end a reducing coupling 25 from which extends a pipe 263 which is connected to coupling 28. Pipe 26 has a regulating valve 21 therein. A conduit 28 is connected through-suitable couplings to T member 24 and the same projects. tangentially into casing I0 and communicates with chamber I 0b therein. It will thus be seen that the air under pressure supplied through conduit 23 is supplied both to the burner I8 and to chamber Nib. A baiiie or regulating member 30 is provided which in the embodiment of the invention illustrated is shown as having airusto-con-i'cal portion 30w Fig. 6 is a view in front elevation of one of I and a short cylindrical portion b projecting therefrom, portion 30b having its internal diameter equal substantially to the external diameter of member H. Member 30 thus extends from the outer side of member I to a line which is closely adjacent the wall of chamber Illb. A pair of rods 3| are connected to the concave side of member 30 and these rods project outwardly through the end wall of casing l0 and through members 32 therein which surround said rods and provide a tight joint. Small brackets and have journaled therein rods 34 provided at 33 are secured to the outer side of cover ||lb their outer ends with hand wheels 35. A collar 36 is secured to each rod at the inner side of bracket 34 and engaged by-a-nut 31. The inner ends of rods 34 are threaded and thus form screws and extend intothe-threaded ends of rods 3|. It will thus be seen that by turning hand wheels 35 rods 3| will be moved inwardly or outwardly, thus moving baflie member 30 toward or away from the inner end of member II. It will be noted that conduit 28 extends into chamber llib between member 36 and the rear end of said chamber. a

The contracted end of casing I0 is provided with a plurality of outwardly extending conduits 40, the passages therethrough communicating with chamber l0b. Said conduits40 are shown as four in number andeach has its outer end threaded to have screwed thereon a collar 4|. Another outer .collar 42 is secured to collar 4| by a plurality of circumferentially spaced screws 43. A diaphragm 44 is placed between collars 4| and 42 and a screen 45 disposed at the outer side of diaphragm 44 is also disposed betweensaid collars. Members 44 and 45 are thus tightly clamped between the collars 4| and 42. While diaphragm 44 might be made of various material, in practice it has been found suitable to have this made from a sheet of asbestos.

The casing 10 is supported upon spaced brackets 48 having concave or segmental supporting surfaces 48a. Said brackets are disposed adjacent the ends of easing Iii and are preferably connected by one or more tie rods 49 extending therebetween. A band 50 extends over the top and around casing Ill at each end thereof and said band has connected to its ends rods 5| which project downwardly and toward the center of brackets 48 and through the outwardly extending flanges 52a of small angle brackets 52 secured to the outer sides of brackets 48. The ends of rods 5| are threaded and equipped with nuts 53 underlying flanges 42a so that the bands 50 can be tightened about casing in to hold the same firmly in place. As shown in Figs. 1, 2 and 3 casing It has a cylindrical outlet conduit l0d projecting centrally from the contracted end of easing Illa. Casing I0 is also shown as having a conduit 54 extending therethrough having a passage communicating with passage liib. Conduit 54 is adapted to have connected thereto a control apparatus, such as a photoelectric cell, for shutting off the gas supply should the flame of the burner be extinguished. V

- In operation the gas will be supplied to burner l8 through the pipe I9 and air under pressure will be supplied to said burner through pipe 23. Air under pressure will also be supplied to chamber IN) by the conduit 28. The air supplied through conduit 28 will be given a whirling or helical motion in casing in due to the tangential disposition of conduit 28. The air in, chamber lpb will be maintained at considerable pressure.

In one embodiment of the invention the air was maintained at 10 pounds pressure and the device was designed to heat the air to 1000 degrees F. With the air in chamber |0b under such pressure there is a possibility of having a back pressure on burner l8. To prevent this and to properly regulate the pressure in the chamber lllb relative to the pressure in the passage of member H, the bafile member 30 will be adjusted. This member 30 can be adjusted by the operator turning the hand wheels 35. The operator will adjust member 30 until the proper and desired flame from burner i8 is secured. When this flame is secured the pressure is properly equalized in the passage of member and in chamber iflb. The burner can thus operate properly burning the gaseous fuel under pressure and the air in chamber lUb can also be maintained under pressure. A high degree of heating efficiency is thus obtained. 7 With such heated air and gas there is always the possibility of an explosion in chamber |0b and'fo'r this purpose the explosion heads comprising conduits 40 and the structure thereon are provided. Should an explosion occur the diaphragrns 44 will be fractured and the gases can escape through the same and screens 45. It may be that both the diaphragm 44 and screen 45 will be blown out by the explosion. A relief is thus provided for the excess pressure so that there is no danger of injuring casing l0.

s From the above description it will be seen that I have provided a simple and efficient device for burning fuel under pressure and heating air under pressure. It is believed that such a device has not heretofore been successfully operated in this country. Such devices are used for heating air to be used in oil refining plants. The Houdry oil-refining process makes use of such heated air at high temperature. The device has been amply demonstrated in actual practice and will soon be in commercial production.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicants invention, which generally stated, consists in a device capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

. What is claimed is:

1. A device for heating air under pressure by burning liquid or gaseous fuel under pressure havingin combination, a cylindrical casing having a chamber therein, a member projecting into said casing and chamber at one end thereof having a passage therethrough, a burner projecting into said passage, means for supplying fuel to saidburn'er, means for supplying air under pressure to said burner, a frusto-conical bailie member extending from said first mentioned member to adjacent the wall of said chamber, means for moving said baffle member toward and from the end of said first mentioned member and means for supplying air tangentially to said chamber between said bafile member and said end of said chamber. 7

I 2. A device for heating air under pressure by burning liquid or gaseous fuel having in combination, a casing having a chamber therein in which air is heated, a burner disposed at one end of said chamber, a passage extending into said chamber from said burner through which the products of combustion are delivered to said chamber, means for supplying fuel to. said burner, means for supplying air under pressure to said burner, means for supplying air under pressure to said chamber, a regulating member within said chamber beyond said passage and having a periphery spaced from the Wall thereof, the same extending transversely in said chamber and having a central opening aligned with said passage and means for moving said member toward and from said passage longitudinally of said chamber toward said means for regulating the pressure in the zone of combustion beyond said burner relative to that in said chamber.

3. The structure set forth in claim 2, said means for supplying air under pressure to said chamber being disposed between said end of said chamber and said regulating member.

4. A device for heating air under pressure by burning liquid or gaseous fuels under pressure having in combination, a casing having a chamber therein in which air is heated, a burner disposed adjacent one end of said chamber, means for supplying fuel and air to said burner, means for supplying air under pressure to said chamber disposed adjacent said end of said chamber, a 

